Metabolism; Digestion and Translocation 273 



by the interruption of conduction upon the removal of 

 the phloem ; and by the failure of the loss of cortex to 

 affect directly this movement of organic substances. 



159. Ringing. In horticultural practice ringing is ap- 

 plied to the removal of a small band of bark encircling the 

 stem of dicotyledonous plants so as to include the cortex 

 and phloem. Sometimes there is made merely a circum- 

 ferential cut through to the wood ring, or a small wire is 

 bound tightly about a limb so as to cut into the bark, 

 but these latter may heal too quickly to effect the result 

 desired. 



The principle is evident. Ringing interrupts the more 

 rapid movement of digested foods toward the roots or 

 basal parts to the detriment and often to the ultimate 

 death of these structures ; but there is an accumulation of 

 foods above the ring, and this may be favorable for the 

 developing fruit. This operation may result in a consider- 

 able increase in the size of the shoot, or in the production 

 of tumors, above the incision. 



Ringing is reported a widespread practice in Europe 

 with grapes and apples, and it is employed to some extent 

 in the United States. It should be used with caution where 

 the plant is expected to serve future usefulness. It may, 

 however, increase or incite productivity, hasten ripening, 

 or enhance the size and quality of fruit. In the latitude 

 of New York the grape is generally ringed during late 

 June. The place of ringing should be between the chief 

 fruiting canes and the main vine, but the exact location 

 will be determined by the system of training. There 

 should be such a development of canes below the ring 

 as to fairly well nourish the main vine and root system. 



